Concurrent Validity of the Garmin Vivofit®4 to Accurately Record Step Count in Older Adults in Challenging Environments

2021 ◽  
pp. 1-9
Author(s):  
Jacinta I. Foster ◽  
Katrina L. Williams ◽  
Barbra H.B. Timmer ◽  
Sandra G. Brauer
Keyword(s):  
Older Adults ◽  
Concurrent Validity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Error Rates ◽  
Percentage Error ◽  
Battery Life ◽  
Intraclass Correlation Coefficients ◽  
Outdoor Walking ◽  
Walking Speeds

There is little evidence of the concurrent validity of commercially available wrist-worn long battery life activity monitors to measure steps in older adults at slow speeds and with real-world challenges. Forty adults aged over 60 years performed a treadmill protocol at four speeds, a 50-m indoor circuit, and a 200-m outdoor circuit with environmental challenges while wearing a Garmin Vivofit®4, the activPAL3™, and a chest-worn camera angled at the feet. The Garmin Vivofit®4 showed high intraclass correlation coefficients2,1 (.98–.99) and low absolute percentage error rates (<2%) at the fastest treadmill speeds and the outdoor circuit. Step counts were underestimated at the slowest treadmill speed and the indoor circuit. The Garmin Vivofit®4 is accurate for older adults at higher walking speeds and during outdoor walking. However, it underestimates steps at slow speeds and when walking indoors with postural transitions.

The Validity of Gait Variability and Fractal Dynamics Obtained From a Single, Body-Fixed Triaxial Accelerometer

2014 ◽  
Vol 30 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Dylan Kobsar ◽  
Chad Olson ◽  
Raman Paranjape ◽  
John M. Barden
Keyword(s):  
Older Adults ◽  
Concurrent Validity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Gait Variability ◽  
Limited Information ◽  
Triaxial Accelerometer ◽  
Healthy Older Adults ◽  
Intraclass Correlation Coefficients ◽  
Dynamic Measures

A single triaxial accelerometer has the ability to collect a large amount of continuous gait data to quantitatively assess the control of gait. Unfortunately, there is limited information on the validity of gait variability and fractal dynamics obtained from this device. The purpose of this study was to test the concurrent validity of the variability and fractal dynamic measures of gait provided by a triaxial accelerometer during a continuous 10 minute walk in older adults. Forty-one healthy older adults were fitted with a single triaxial accelerometer at the waist, as well as a criterion footswitch device before completing a ten minute overground walk. The concurrent validity of six outcome measures was examined using intraclass correlation coefficients (ICC) and 95% limits of agreement. All six dependent variables measured by the accelerometer displayed excellent agreement with the footswitch device. Mean parameters displayed the highest validity, followed by measures of variability and fractal dynamics in stride times and measures of variability and fractal dynamics in step times. These findings suggest that an accelerometer is a valid and unique device that has the potential to provide clinicians with valid quantitative data for assessing their clients’ gait.

scholarly journals Validity of Inertial Sensors for Assessing Balance Kinematics and Mobility during Treadmill-Based Perturbation and Dance Training

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3065
Author(s):  
Ernest Kwesi Ofori ◽  
Shuaijie Wang ◽  
Tanvi Bhatt
Keyword(s):  
Concurrent Validity ◽  
Inertial Sensors ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Human Motion ◽  
Intraclass Correlation Coefficients ◽  
Dance Training ◽  
Silver Standard ◽  
Mean Square Errors ◽  
Reactive Balance

Inertial sensors (IS) enable the kinematic analysis of human motion with fewer logistical limitations than the silver standard optoelectronic motion capture (MOCAP) system. However, there are no data on the validity of IS for perturbation training and during the performance of dance. The aim of this present study was to determine the concurrent validity of IS in the analysis of kinematic data during slip and trip-like perturbations and during the performance of dance. Seven IS and the MOCAP system were simultaneously used to capture the reactive response and dance movements of fifteen healthy young participants (Age: 18–35 years). Bland Altman (BA) plots, root mean square errors (RMSE), Pearson’s correlation coefficients (R), and intraclass correlation coefficients (ICC) were used to compare kinematic variables of interest between the two systems for absolute equivalency and accuracy. Limits of agreements (LOA) of the BA plots ranged from −0.23 to 0.56 and −0.21 to 0.43 for slip and trip stability variables, respectively. The RMSE for slip and trip stabilities were from 0.11 to 0.20 and 0.11 to 0.16, respectively. For the joint mobility in dance, LOA varied from −6.98–18.54, while RMSE ranged from 1.90 to 13.06. Comparison of IS and optoelectronic MOCAP system for reactive balance and body segmental kinematics revealed that R varied from 0.59 to 0.81 and from 0.47 to 0.85 while ICC was from 0.50 to 0.72 and 0.45 to 0.84 respectively for slip–trip perturbations and dance. Results of moderate to high concurrent validity of IS and MOCAP systems. These results were consistent with results from similar studies. This suggests that IS are valid tools to quantitatively analyze reactive balance and mobility kinematics during slip–trip perturbation and the performance of dance at any location outside, including the laboratory, clinical and home settings.

Using Pedometers to Estimate Ambulatory Physical Activity in Vietnam

2011 ◽  
Vol 8 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Au Bich Thuy ◽  
Leigh Blizzard ◽  
Michael Schmidt ◽  
Costan Magnussen ◽  
Emily Hansen ◽  
...  
Keyword(s):  
Physical Activity ◽  
Concurrent Validity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Population Based ◽  
Work Activities ◽  
Intraclass Correlation Coefficients ◽  
Significant Difference ◽  
Day Of The Week ◽  
Population Based Survey

Background:Pedometer measurement of physical activity (PA) has been shown to be reliable and valid in industrialized populations, but its applicability in economically developing Vietnam remains untested. This study assessed the feasibility, stability and validity of pedometer estimates of PA in Vietnam.Methods:250 adults from a population-based survey were randomly selected to wear Yamax pedometers and record activities for 7 consecutive days. Stability and concurrent validity were assessed using intraclass correlation coefficients (ICC) and Spearman correlation coefficients.Results:Overall, 97.6% of participants provided at least 1 day of usable recordings, and 76.2% wore pedometers for all 7 days. Only 5.2% of the sample participants were involved in work activities not measurable by pedometer. The number of steps increased with hours of wear. There was no significant difference between weekday and weekend in number of steps, and at least 3 days of recordings were required (ICC of the 3 days of recordings: men 0.96, women 0.97). Steps per hour were moderately correlated (men r = .42, women r = .26) with record estimates of total PA.Conclusions:It is feasible to use pedometers to estimate PA in Vietnam. The measure should involve at least 3 days of recording irrespective of day of the week.

scholarly journals Reliability, Internal Consistency, and Validity of Data Obtained With the Functional Gait Assessment

2004 ◽  
Vol 84 (10) ◽  
pp. 906-918 ◽  
Author(s):  
Diane M Wrisley ◽  
Gregory F Marchetti ◽  
Diane K Kuharsky ◽  
Susan L Whitney
Keyword(s):  
Internal Consistency ◽  
Concurrent Validity ◽  
Physical Therapist ◽  
Rank Order ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Vestibular Disorders ◽  
Intraclass Correlation Coefficients ◽  
Gait Assessment ◽  
Functional Gait

Background and Purpose. The Functional Gait Assessment (FGA) is a 10-item gait assessment based on the Dynamic Gait Index. The purpose of this study was to evaluate the reliability, internal consistency, and validity of data obtained with the FGA when used with people with vestibular disorders. Subjects. Seven physical therapists from various practice settings, 3 physical therapist students, and 6 patients with vestibular disorders volunteered to participate. Methods. All raters were given 10 minutes to review the instructions, the test items, and the grading criteria for the FGA. The 10 raters concurrently rated the performance of the 6 patients on the FGA. Patients completed the FGA twice, with an hour's rest between sessions. Reliability of total FGA scores was assessed using intraclass correlation coefficients (2,1). Internal consistency of the FGA was assessed using the Cronbach alpha and confirmatory factor analysis. Concurrent validity was assessed using the correlation of the FGA scores with balance and gait measurements. Results. Intraclass correlation coefficients of .86 and .74 were found for interrater and intrarater reliability of the total FGA scores. Internal consistency of the FGA scores was .79. Spearman rank order correlation coefficients of the FGA scores with balance measurements ranged from .11 to .67. Discussion and Conclusion. The FGA demonstrates what we believe is acceptable reliability, internal consistency, and concurrent validity with other balance measures used for patients with vestibular disorders.

scholarly journals E Test versus Agar Dilution for Antimicrobial Susceptibility Testing of Viridans Group Streptococci

1999 ◽  
Vol 37 (1) ◽  
pp. 26-30 ◽  
Author(s):  
S. J. Rosser ◽  
M. J. Alfa ◽  
S. Hoban ◽  
J. Kennedy ◽  
G. K. Harding
Keyword(s):  
Antimicrobial Agents ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Error Rates ◽  
Culture Methods ◽  
Intraclass Correlation Coefficients ◽  
Laboratory Variables ◽  
Agar Dilution ◽  
Bacteremic Episode ◽  
Viridans Group Streptococci

Viridans group streptococci (VGS) are commonly isolated from the blood of hospitalized patients. The E test represents a convenient method for determining the MICs for VGS, but for this purpose it has not been well validated against reference methods. In this study, 180 unselected VGS isolates were identified to a species level, and the MICs of penicillin, cefuroxime, cefotaxime, and vancomycin were determined by both agar dilution and the E test. Available data regarding demographic and laboratory variables for each VGS bacteremic episode were collected, the significance of each VGS isolate was assessed, and the associations between and among laboratory and clinical variables were investigated. Among all VGS isolates, 68.3% (median of three runs) were found to be fully susceptible to penicillin by agar dilution. The E test and agar dilution showed average agreements (within ±1 dilution) of 92.2% for penicillin, 95.7% for cefuroxime 91.3% for cefotaxime, and 86.7% for vancomycin. Agreements over serial E tests and serial agar dilutions were excellent for β-lactam agents (intraclass correlation coefficients, >0.9) but less impressive for vancomycin. Very major error rates for the E test were ≤0.7%, and combined major and minor error rates were within acceptable limits for all antimicrobial agents tested. Lysis-centrifugation culture methods were more often associated with clinically insignificant VGS isolates; otherwise, no associations between clinical and laboratory variables were noted.

Accuracy of the Fitbit Zip for Measuring Steps for Adolescents With Visual Impairments

2017 ◽  
Vol 34 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Justin A. Haegele ◽  
Ali S. Brian ◽  
Donna Wolf
Keyword(s):  
Intraclass Correlation ◽  
Visual Impairments ◽  
Correlation Coefficients ◽  
Criterion Validity ◽  
Intraclass Correlation Coefficients ◽  
Paired Samples ◽  
Lead Investigator ◽  
Walking Speeds ◽  
Mobility Device ◽  
Study Participants

Our purpose in this study was to document the criterion validity of the Fitbit Zip for measuring steps taken by youth with visual impairments (VI). A secondary purpose was to determine whether walking pace, mounting position, or relative position to the user’s mobility device impacted the criterion validity of the device. Fourteen adolescent-aged individuals (Mage = 15.4; 13 male and 1 female) with VI participated in this study. Participants wore four Fitbit Zips at different mounting positions and completed two, 2-min walking trials while the lead investigator hand tallied steps. Measurement validity was analyzed using absolute percent error (APE), intraclass correlation coefficients estimated level of conformity, and paired samples t tests and Cohen’s d effect sizes assessed APE relative to mounting positions. Results supported the use of the Fitbit Zip during regular-paced walking; however, caution must be used during activities exceeding regular walking speeds, as devices consistently underestimated steps.

scholarly journals Prescribing Target Running Intensities for High-School Athletes: Can Forward and Backward Running Performance Be Autoregulated?

Sports ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 77 ◽  
Author(s):  
Aaron Uthoff ◽  
Jon Oliver ◽  
John Cronin ◽  
Paul Winwood ◽  
Craig Harrison
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Percentage Error ◽  
High School Athletes ◽  
Running Speed ◽  
Running Performance ◽  
Youth Athletes ◽  
Intraclass Correlation Coefficients ◽  
Relative Consistency ◽  
Maximum Effort

Target running intensities are prescribed to enhance sprint-running performance and progress injured athletes back into competition, yet is unknown whether running speed can be achieved using autoregulation. This study investigated the consistency of running intensities in adolescent athletes using autoregulation to self-select velocity. Thirty-four boys performed 20 m forward running (FR) and backward running (BR) trials at slow, moderate and fast intensities (40–55%, 60–75% and +90% maximum effort, respectively) on three occasions. Absolute and relative consistency was assessed using the coefficient of variation (CV) and intraclass correlation coefficients (ICC). Systematic changes in 10 and 20 m performance were identified between trials 1–2 for moderate and fast BR (p ≤ 0.01) and during moderate BR over 20 m across trials 2–3 (p ≤ 0.05). However, comparisons between trials 2–3 resulted in low typical percentage error (CV ≤ 4.3%) and very good to excellent relative consistency (ICC ≥ 0.87) for all running speeds and directions. Despite FR being significantly (p ≤ 0.01) faster than BR at slow (26%), moderate (28%) and fast intensities (26%), consistency was similar in both running directions and strongest at the fastest speeds. Following appropriate familiarization, youth athletes may use autoregulation to self-select prescribed FR and BR target running intensities.

scholarly journals A Digital Photographic Measurement Method for Quantifying Foot Posture: Validity, Reliability, and Descriptive Data

2011 ◽  
Vol 46 (1) ◽  
pp. 20-30 ◽  
Author(s):  
Stephen C. Cobb ◽  
C. Roger James ◽  
Matthew Hjertstedt ◽  
James Kruk
Keyword(s):  
Concurrent Validity ◽  
Measurement Method ◽  
Injury Risk ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Validity And Reliability ◽  
Descriptive Data ◽  
Data Set ◽  
Intraclass Correlation Coefficients ◽  
Foot Posture

Abstract Context: Although abnormal foot posture long has been associated with lower extremity injury risk, the evidence is equivocal. Poor intertester reliability of traditional foot measures might contribute to the inconsistency. Objectives: To investigate the validity and reliability of a digital photographic measurement method (DPMM) technology, the reliability of DPMM-quantified foot measures, and the concurrent validity of the DPMM with clinical-measurement methods (CMMs) and to report descriptive data for DPMM measures with moderate to high intratester and intertester reliability. Design: Descriptive laboratory study. Setting: Biomechanics research laboratory. Patients or Other Participants: A total of 159 people participated in 3 groups. Twenty-eight people (11 men, 17 women; age  =  25 ± 5 years, height  =  1.71 ± 0.10 m, mass  =  77.6 ± 17.3 kg) were recruited for investigation of intratester and intertester reliability of the DPMM technology; 20 (10 men, 10 women; age  =  24 ± 2 years, height  =  1.71 ± 0.09 m, mass  =  76 ± 16 kg) for investigation of DPMM and CMM reliability and concurrent validity; and 111 (42 men, 69 women; age  =  22.8 ± 4.7 years, height  =  168.5 ± 10.4 cm, mass  =  69.8 ± 13.3 kg) for development of a descriptive data set of the DPMM foot measurements with moderate to high intratester and intertester reliabilities. Intervention(s): The dimensions of 10 model rectangles and the 28 participants' feet were measured, and DPMM foot posture was measured in the 111 participants. Two clinicians assessed the DPMM and CMM foot measures of the 20 participants. Main Outcome Measure(s): Validity and reliability were evaluated using mean absolute and percentage errors and intraclass correlation coefficients. Descriptive data were computed from the DPMM foot posture measures. Results: The DPMM technology intratester and intertester reliability intraclass correlation coefficients were 1.0 for each tester and variable. Mean absolute errors were equal to or less than 0.2 mm for the bottom and right-side variables and 0.1° for the calculated angle variable. Mean percentage errors between the DPMM and criterion reference values were equal to or less than 0.4%. Intratester and intertester reliabilities of DPMM-computed structural measures of arch and navicular indices were moderate to high (&gt;0.78), and concurrent validity was moderate to strong. Conclusions: The DPMM is a valid and reliable clinical and research tool for quantifying foot structure. The DPMM and the descriptive data might be used to define groups in future studies in which the relationship between foot posture and function or injury risk is investigated.

scholarly journals Psychometrics of the Wrist Stability and Hand Mobility Subscales of the Fugl-Meyer Assessment in Moderately Impaired Stroke

2015 ◽  
Vol 95 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Stephen J. Page ◽  
Erinn Hade ◽  
Andrew Persch
Keyword(s):  
Upper Extremity ◽  
Internal Consistency ◽  
Concurrent Validity ◽  
Intraclass Correlation ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Outpatient Rehabilitation ◽  
Finger Movement ◽  
Intraclass Correlation Coefficients ◽  
Upper Extremity Movement

Background There remains a need for a quickly administered, stroke-specific, bedside measure of active wrist and finger movement for the expanding stroke population. The wrist stability and hand mobility scales of the upper extremity Fugl-Meyer Assessment (w/h UE FM) constitute a valid, reliable measure of paretic UE impairment in patients with active wrist and finger movement. Objective The aim of this study was to determine performance on the w/h UE FM in a stable cohort of survivors of stroke with only palpable movement in their paretic wrist flexors. Design A single-center cohort study was conducted. Method Thirty-two individuals exhibiting stable, moderate upper extremity hemiparesis (15 male, 17 female; mean age=56.6 years, SD=10.1; mean time since stroke=4.6 years, SD=5.8) participated in the study, which was conducted at an outpatient rehabilitation clinic in the midwestern United States. The w/h UE FM and Action Research Arm Test (ARAT) were administered twice. Intraclass correlation coefficients (ICCs), Cronbach alpha, and ordinal alpha were computed to determine reliability, and Spearman rank correlation coefficients and Bland-Altman plots were computed to establish validity. Results Intraclass correlation coefficients for the w/h UE FM and ARAT were .95 and .99, respectively. The w/h UE FM intrarater reliability and internal consistency were greater than .80, and concurrent validity was greater than .70. This also was the first stroke rehabilitative study to apply ordinal alpha to examine internal consistency values, revealing w/h UE FM levels greater than .85. Concurrent validity findings were corroborated by Bland-Altman plots. Conclusions It appears that the w/h UE FM is a promising tool to measure distal upper extremity movement in patients with little active paretic wrist and finger movement. This finding widens the segment of patients on whom the w/h UE FM can be effectively used and addresses a gap, as commonly used measures necessitate active distal upper extremity movement.

scholarly journals Comparison between Mother, ActiGraph wGT3X-BT, and a hand tally for measuring steps at various walking speeds under controlled conditions

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2799 ◽  
Author(s):  
Henrik Riel ◽  
Camilla Rams Rathleff ◽  
Pernille Møller Kalstrup ◽  
Niels Kragh Madsen ◽  
Elena Selmar Pedersen ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Average Error ◽  
Intraclass Correlation Coefficients ◽  
Controlled Conditions ◽  
Identical Number ◽  
All Speeds ◽  
Walking Speeds ◽  
The Relationship ◽  
Healthy Participants

IntroductionWalking is endorsed as health enhancing and is the most common type of physical activity among older adults. Accelerometers are superior to self-reports when measuring steps, however, if they are to be used by clinicians the validity is of great importance. The aim of this study was to investigate the criterion validity of Mother and ActiGraph wGT3X-BT in measuring steps by comparing the devices to a hand tally under controlled conditions in healthy participants.MethodsThirty healthy participants were fitted with a belt containing the sensor of Mother (Motion Cookie) and ActiGraph. Participants walked on a treadmill for two minutes at each of the following speeds; 3.2, 4.8, and 6.4 km/h. The treadmill walking was video recorded and actual steps were subsequently determined by using a hand tally. Wilcoxon’s signed ranks test was used to determine whether Mother and ActiGraph measured an identical number of steps compared to the hand tally. Intraclass correlation coefficients were calculated to determine the relationship and Root Mean Square error was calculated to investigate the average error between the devices and the hand tally. Percent differences (PD) were calculated for between-instrument agreement (Mother vs. the hand tally and ActiGraph vs. the hand tally) and PDs below 3% were interpreted as acceptable and clinically irrelevant.ResultsMother and ActiGraph under-counted steps significantly compared to the hand tally at all walking speeds (p < 0.001). Mother had a median of total differences of 9.5 steps (IQR = 10) and ActiGraph 59 steps (IQR = 77). Mother had smaller PDs at all speeds especially at 3.2 km/h (2.5% compared to 26.7%). Mother showed excellent ICC values ≥0.88 (0.51–0.96) at all speeds whilst ActiGraph had poor and fair to good ICC values ranging from 0.03 (−0.09–0.21) at a speed of 3.2 km/h to 0.64 (0.16–0.84) at a speed of 6.4 km/h.ConclusionMother provides valid measures of steps at walking speeds of 3.2, 4.8, and 6.4 km/h with clinically irrelevant deviations compared to a hand tally while ActiGraph only provides valid measurements at 6.4 km/h based on the 3% criterion. These results have significant potential for valid objective measurements of low walking speeds. However, further research should investigate the validity of Mother in patients at even slower walking speeds and in free-living conditions.

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